Telephone-receiver.



J. T. CURTIS.

. TELEPHONE RECEIVER.

APPLIOATION FILED JULY a, 1907.

908,846. 4 PatentedJanfi, 1909. 1 j J4 j/ i 12 ZWM If:

' $45 fizz/2%;

UNITED PATENT orrionv JESSE TEMPLE OUR'IIS, OF BEMENT, ILLINOIS;

TELEPHONE-RECEIVER.

Specification'of Letters Patent.

Patented Jan. 5, 1909,

Application filed July 9, 1907. Serial No. 382,838.

' pole pieces carrying the coils thereto. Provision is also made, for putting the. diaphragm under initial stress or tension by tubular shell 5 closed at shown at 6..

means engaging the diaphragm close to its periphery and there so clamping said diaphragm that it is subjected at all times to a stress or strain in 'a plane at right angles to the thickness of the diaphragm. Furthermore, there are provided means whereby the distance of the diaphragm .from the polar extremities of the electro-magnet may be" adjusted and the parts, when once adjusted, be locked in such position.

The invention will be from the following detailed description, taken in ponnection with the accompanying drawing forming part of this specification, in which,

Figure 1 is a central section through the improved receiver, with parts shown 'in elevation; and Fig. 2 is a horizontal section, also with parts shown in elevation.

' Referring to the drawings, there is shot-in a casing composed of a cup-shaped or approximately semispherical part 1 reduced at its open end to form a neck 2 'oined to the part 1 by a continuation of the neck constituting a shoulder 3. Projecting from one side of the cup 1. is another externallythreaded neck 4 receiving one end of a the other end, as

Screwed on to the neck 2 is an expanded or bell-shaped shell 7 formed into an invert neck 8 at its wider end remote from the point where it is screwed on the neck 2. The neck 8 is internally threaded and terminates in an interior ledge 9 having a beveled seat 10 formed thereon. Screwed into the threaded portion of the neck cl is an annulus i1 provided with a beveled inner edge 12 matching the beveled portion 10 of the ledge 9, while an annular llangc may be formed aroui d the outer end of the annulus. T he annul s fully understdod 11 is furthermore provided with interior threads to receive an ear piece 14, which latter may be of the shape usually employed in telephone receivers.

The neck or continuation 4 of the cup 1 is provided with through passages for the legs ofa permanent horse-shoe magnet 15, which" may be constructed, if desired, in the manner usually employed in telephone practice. This magnet has its polar ex-v tremitiesrecessed to receive soft iron pole pieces 16, separated, if need be, by a nonmagnetic block 17.

The pole pieces 16 are disposed so as to project at right angles to the length of the.

legs of the magnet 1 5 and beyond the latter receive coils 18 such as are commonly employed in connection with magneto telephones.

In the drawings the circuit connections have been omitted as being unnecessary for the understanding of the present invention, but it will beunderstood that the leads to the coils 18 may be arranged in any suitable manner. The shell 5, when the instrument is in use, will constitute the hand-hold of the telephone, thus bringing the ear piece 14 into convenient position to be applied to the ear without fatigue to the arm of the user.

The legs of themagnet 15 are provided with short longitudinal slots 19 through which is passed a screw 20 the head of which. may be made to engage one of the legs of the magnet and a threaded portion of the screw may be made to enter a suitably tapped hole in the neck OI'.(-.\'tOl1'Sl,0n d, or be otherwise secured, so, that on loosening the scrcw the magnet may be adjusted longitudinally, and when the desired longitudinal adjustment is attained the screw maybe seated with its head against the magnet so as-to firmly retain the latter in the adjusted position.

The purpose of adjusting the permanent magnet is to clamp thepole pieces 16 thereto, and that this may be done the neck or extension et is provided with a-"finger 21 located between the two legs of the magnet, so that when the magnet is moved in the proper direction this finger will abut against the pole pieces 16 and so clamp the same in the seats therefor provided in the ends bl the magnet logs.

When it is desired to dismantle the instrument for any purpose it is simply necessary to loosen the screw 20 when the magnet 15 willbc moved away from the linger 2 in a sufli'cient extent to loosen the pole pieces 16 and said pole piecesmay be easily withdrawn from their seats in the' magnet.

The diaphragm 22 may be an ordinary ferrotype disk and is of such size that it may be seated with the portion immediately ad- 'a'cent to the periphery resting upon the eveled portion 10 of the led e 9. Now, when the annulus 11 is screwed own toward the ledge 9 its beveled portion 12 will engage the extreme edge of the diaphragm and up set the same on to the beveledseat 10. This will serve to stretch the-diaphragm tightly,

and, therefore, put it under. initial stress when the-annulus 11 has been screwed home. By this means the diaphragm is put under an initial high stress and is so maintained under the conditions. of operation, whereby the diaphragm is keptin a most eflicient condition, and by reason of the mechanical stress will permit of a very close adjustment to the magnets 16, thus realizing the full value of the magnetic variations when the receiver is in operation.

Having lgcked the magnet coils properly in place, the shell 5 may be screwed on to the neck 'or extension 4.

After the dia hragm has been properly seated in the she I 7 the latter is screwed on to the neck 2 to the desired extent to bring the diaphragm to such a distance from the extremities of the pole pieces or cores 16- as may befound most eflicient, when a locking ring 23 applied to the shell 7 exterior to the portion which is screwed on to'the neck 2 may be brought down into contact with the shoulder 3 and thereby lock the shell 7 firmly to the cup-shaped body 1.

j The parts being all assembled and the electric connections suitably made, the telephone receiver is rasped .in the hand of the user by means 0% the shell 5, which need only be heldupright to bring the ear piece 14 opposite the ear of the user, in an easy and natural position.

The several non-metallic parts of the telephone may be made of vulcanized rubber or other suitablematerial, and the screw connections may be reinforced with metal if so jthe diaphragm a condition of permanent stress in a plane at right angles to the vibration of said dia hragm.

2. In a telep one, a diaphragm, an annular beveled support for the same receiving the diaphragm adjacent to the periphery of the latter, and a clamp ring or annulus having a beveled edge coacting with the beveled seat for the diaphragm for permanentl'y bending the peripheral portion of said diaphragm into said beveled seat and thereby putting the diaphragm under initial stress in a plane at right angles to the plane of vibration of the diaphra m and at, the same time clamping the'dia Iiragm in place.

3. In "a telephone, a suita le casing, a permanent magnet adjustable longitudinally therein, pole pieces carried by the magnet and seated in the legs thereof and having a fixed portion of the telephone casing in the path of said pole pieces, and means for securing the. magnet to the casing when in the adjusted position to lock the pole pieces in place. j I

4. In a telephone, a suitable casing, a permanent horse-shoe magnet having 0 said casing for longitudinal movement therein, a screw engaging the casing and passing through the slots in the magnet, and pole ieces seated in the magnet and having a ed portion of the casing inthe ath thereof, whereby the pole pieces may e clamped between their seats and the said fixed portion of thecasing'and there held by the screw engaging the magnet.

5. A. telephone comprising a casing section having a threaded extension on one side and a threaded opening at another point, ahand-hold composed of a shell secured to the extended portion of the firstmentioned part of the casing, a permanent magnet adjustably secured in the casing and having removable pole pieces extending through the open end of the first mentioned part of the casing, witha fixed portion of the casing in engagement with the said pole pieces, a diaphragm carrier adjustably secured to the open end of the first mentioned portion of the casing and rovided with a beveled annular seat, a dia agm carried by said seat, a locking ring or the diaphragm having a beveled engaging portion for clamping the diaphragm and putting the latter under strain in a plane at right angles to the nglt'udinal slots in the'legs thereof and seated in plane of vibration of said diaphragm, and

another locking ring for securing the diaphragm carrier in its adjusted position.

6. A telephone receiver comprising a shell constituting a hand-hold, a diaphragm holder, aconnection between the diaphragm sion and the die phragm holder being threadsion, and a locking ring exterior to the In' testimony that I claim the foregoing 'as my own, I have-hereto affixed my signature in the presence of two witnesses.

v JESSE TEMPLE CURTIS. diaphragm holder and threaded to engage Witnesses: v the same to look the diaphl agm hokler in GERTRUDE DUNCAN, adjusted positions. r g MAYME MGNAMEE.

ed toreeeive said extension end'also threadedexterior to the part receiving the exten- 

